This interview with Tae Hea Nahm, managing director of the venture capital firm Storm Ventures, was conducted and condensed by Adam Bryant.

Q. What were some early influences for you?

A. I was born in South Korea, and we immigrated to St. Louis when I was 5 years old. In the beginning, it was all about learning how to get acclimated to life in the United States. I remember starting kindergarten not being able to speak English. I felt like I was going to flunk kindergarten, but somehow survived.

Tell me about your parents.

My father was a medical school professor in Korea and became a doctor here in the United States. My mother was very hard-driving. If I got 99 on a test, the first question was, “Why didn’t you get 100?” If I got 100, the next question was, “Can you do it again?”

That pressure can be hard on some people.

I wasn’t happy about it, but once I went to college and met other Korean students like myself, I realized we were all sort of trained the same way — almost like thoroughbreds to run races. After a while I just learned to accept it for what it is. It’s not a question of good or bad; it’s how we got trained.

But I almost felt like I had a second set of parents because my brother and sister are 12 and 14 years older than I am. My sister is an architect, and very artistic. My brother is as logical as you can be, and he became a medical school professor. I remember listening to a lot of family debates where it was almost like two ships passing in the night because there wasn’t a fundamental basis of communication. Their perspectives were so different.

That taught me the importance of really trying to understand others and their motivations, because so much depends on their backgrounds and their perspectives in terms of how they’re going to make decisions.

Did you have an idea of what you wanted to do for a career when you went to college?

I was an applied math major. I really like modeling and trying to understand and predict things. As you might expect, given my father’s and brother’s careers, there was tremendous pressure to follow in their footsteps. But I wanted to be different.

I actually wanted to program and then go to business school, and we ended up compromising on law school, and that’s how I ended up in law school. For a Korean family, law is a profession that is close to medicine. My friends were all shocked that I went to law school because I was so hard-core about math and science.

It worked out fine because I felt comfortable with technology and wanted to work with companies. I ended up joining a law firm in Silicon Valley, and over many years, I worked with several hundred start-ups.

Then you decided to become a venture capitalist. What did you learn from the transition?

After we started Storm Ventures, we incubated a company, and I was the founding C.E.O. I hired the first 24 employees. As C.E.O., I learned firsthand what an emotional roller coaster it is to run a company. You can feel so high and so low in the space of a single day. Now, when I work with start-up C.E.O.s and they tell me life is so great, I figure it’s never that great, and when they tell me it’s so bad, it’s never so bad.

The other thing I learned as C.E.O. is that it’s very lonely. If you share all the doubts and fears with people, then people sort of freak out, whether they’re other investors or employees or executives. You have to provide a path to success. So what I found as C.E.O. is that you almost need a split personality.

On the one hand, you have to appear like Moses, so that people believe that you’re going to take them to the Promised Land. And you have to present a very simple, clear path to success. On the other hand, if you just believe all of that, you can easily run the company off a cliff. Being a C.E.O. requires a lot of faith and passion, but for making decisions, sometimes truth and faith are different.

So you also have to be a skeptic, almost like Galileo. You can have beliefs, but you have to really search for the truth, which is often tied to bad news.

You’ve worked with hundreds of entrepreneurs. What’s the most important quality that sets the best ones apart?

The most important thing is just sheer passion. It doesn’t mean the person’s naturally a great salesperson. Somebody can be really shy and introverted, and you’d think they would be horrible at selling. But for their particular idea, they’re just so passionate about it and they have this clarity of vision. That forms the basis for creating something great out of nothing. And you’re not trying to pursue 100 things. You’re pursuing that one, focused effort.

You’ve observed a lot of different corporate cultures in action, too. What makes the biggest difference in terms of culture?

Culture, to me, is about getting people to make the right decision without being told what to do. No matter what people say about culture, it’s all tied to who gets promoted, who gets raises and who gets fired. You can have your stated culture, but the real culture is defined by compensation, promotions and terminations. Basically, people seeing who succeeds and fails in the company defines culture. The people who succeed become role models for what’s valued in the organization, and that defines culture.

If the C.E.O. can outline, as part of the vision statement, what the stated culture is, and if that official proclamation of culture is aligned and consistent with the unofficial culture — based on who gets raises and promotions and who gets fired — then you have the best culture. When the two are disconnected, you have chaos.